Lake Homes and Cottages in Port Stanley: Seasonal Moisture and Mold

Cottage mold in Port Stanley is mostly a result of two things: humid air off Lake Erie and buildings that sit closed and unheated for months. Moisture gets in, nothing moves it out, and soft materials stay damp long enough to grow mold. Good closing and opening routines prevent most of it, and the rest comes down to the crawlspace and the lake-facing walls.

Why cottage mold in Port Stanley is so common

A house that is lived in all year has a furnace or air conditioner running, people opening doors, and someone who notices a drip. A seasonal cottage has none of that from fall to spring. The indoor air follows the outdoor air, and beside the lake that air is damp for much of the year.

The swing seasons do the damage. In spring the building is still cold from winter. Warm, moist air drifts in and condenses on cold surfaces: window glass, the backs of furniture, mattresses, the inside of closets and cupboards. In fall the reverse happens as the building cools down around the moisture it collected over the summer. With the curtains closed and no air moving, those surfaces can stay damp for weeks.

Many older cottages in the village were built for summer use only and were later insulated or converted for year-round living. Wall cavities that used to dry freely can hold moisture once insulation and new interior finishes are added, especially when a rental season adds daily showers and cooking for a full house.

Crawlspaces, piers and sandy ground

A lot of cottages near the beach and harbour sit on piers or shallow crawlspaces over sand instead of full basements. The space underneath is open to damp lake air and often to wind-blown sand and rain. The floor framing and subfloor take up that moisture from below. Cupped floorboards, a musty smell that is strongest at floor level and sagging insulation under the floor are the usual signs.

Skirting around the base of a cottage keeps animals out, but solid skirting with no dry ground cover can trap damp air under the floor. A vapour barrier laid over the soil makes a noticeable difference to the rooms above.

Wind-driven rain on the lake side

Storms come in off Lake Erie with strong wind behind them. Rain is pushed sideways against the lake-facing wall and into any gap around windows, doors, deck ledger boards and siding joints. A wall like that can leak a little in every storm for years and show nothing indoors but a faint stain under a window.

Check the caulking and flashing on that side each spring, and look closely at the wall where a deck attaches to the building. A thermal camera and moisture meter can show whether the framing under a window is wet without opening the wall.

Closing and opening checklist

At closing in the fall:

• Shut off the water and drain the lines, the water heater and the traps, or have a plumber winterize the system.
• Empty and prop open the fridge and freezer.
• Stand mattresses and cushions on edge, away from exterior walls, and leave closet and cupboard doors open.
• Remove wet items: towels, life jackets, bath mats and damp firewood.
• Leave interior doors open so air can move through the whole building.

At opening in the spring:

• Walk the whole place before turning anything on, and look at ceilings, under sinks and inside closets.
• Turn the water on slowly with a second person watching for leaks. Pipes that froze and split over the winter only show themselves once the pressure is back.
• Open windows on a dry day and get air moving, then run a dehumidifier.
• Wash or dry in the sun any fabrics that smell musty.
• Look under the building at the floor framing with a flashlight.

A dehumidifier left running over the winter only helps if the building is kept above freezing and the unit drains to a drain on its own. A bucket that fills in two days does nothing for the next five months.

When cleaning is enough and when it is not

Surface mildew on a window sill, a bathroom ceiling or a hard piece of furniture can be washed off with detergent and water once the space is dry. Mold that has grown into drywall, ceiling tile, carpet, mattresses or the floor framing is different. Those materials are removed or professionally cleaned under containment, and the framing is dried to under 16% wood moisture content. Health Canada advises removing indoor mold whatever the type, and anyone with asthma or allergies should leave the cleanup to others.

Most crawlspace and lower-level mold jobs run $1,200 to $9,500. If you rent the cottage out, deal with any smell before the season starts and keep the report with your records. A good first step this weekend is a flashlight check under the floor and along the lake-side windows.

Common questions